Compound extracted from husk and fruit stem of Xanthoceras sobifolia and its extracting method and use thereof

ABSTRACT

A method on its extraction: grinding the husk and fruit stem of Xanthoceras sobifolia into particles, extracting the particles with solvents, filtrating, reclaiming the solvent and collecting the concentrated solution, passing the collection through macroporous resin, eluting it by solvent, reclaiming the solvent to get the enriched solution, drying the solution to form a brown solid which called total saponins; then dissolving the total saponins in water, extracting by normal butyl alcohol, having the extraction dried to obtain brown powder, chromatographing the powder resolved solution by silica gel column repeatedly, receipting the gradient elution with 100:(35˜60) chloroform:methanol, reclaiming the eluted solution, refining and re-crystallize the left solution, will obtain the white raphide which is the invention compound—Xanthoceraside. It is verified that the compound can be used to make medicine to treat brain diseases and tumors, and to make health food to prevent and cure brain diseases and tumors.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No. 11/631,637 filed on Jan. 5, 2007, which in turn is a National Stage Entry of PCT/CN05/00988 filed on Jul. 5, 2005, which claims priority from CN 200410020921.0 filed Jul. 7, 2004, the disclosures of which are relied on and incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to the technology and method developed and used to discover the composition and application of an extracted compound from Husk and Fruit Stem of Xanthoceras sobifolia (or Xanthoceras sobifolia Bunge).

BACKGROUND ART

Xanthoceras sobifolia Bunge, belonging to genus Xanthoceras family Sapindaceae, is a kind of woody oil-bearing plant endemic to China. There is only one species in the genus. The plant mainly distributes in Liaoning Province, Inner Mongolia Autonomous Region and Hexi corridor in Gansu Province in China. It has the drought resistant, cold hardy, barren land enduring, saline and alkali tolerant, and high anti-pest characteristics, also has easy regeneration, early fecundity and long-life properties. There are about 700,000 Mu (about 47,000 hectares) of it growing in the northern area of China for sand fixed forest.

Xanthoceras sobifolia's kernel contains oil up to 60%, which consisting of 14 unsaturated fatty acids. The oil is edible, tastes pleasant and can be used to treat enuresis on infant. So far, the husk and the fruit stem of Xanthoceras sobifolia have been considered as abandoned resource and have not been developed and used to benefit human beings.

DISCLOSURE OF INVENTION

The aim of the present invention is to provide the compound from the husk and fruit stem of Xanthoceras sobifolia, its extracted and refined methods, and its applications on medicine. This invention will not only have the trashed husk and fruit stem of Xanthoceras sobifolia as a useful resource, but also develop a new medicine to treat brain diseases and tumors.

In order to realize the purposes above-mentioned, the technical procedure of the invention is as follows:

The present invention offers the compound from the husk and fruit stem of Xanthoceras sobifolia, which is named as Xanthoceraside, classifying to triterpenoid saponins. Its chemical structure is as follows:

3-O-(α-L-arabinofuranosyl(1→3)-β-D-galactopyranosyl(1→2))-β-D-glucuronopyranosyl-21,22-diangeloyl-R₁-barrigenol

The compound is a kind of white raphide, melting point between 267˜268° C. When measuring it with spectrophotometer at 254 nm wavelength, the Cambridge (faint) red stain is emerged, and when dissolved into sulfuric acid solution it appears transparent purple. Its Molish reaction is positive.

The extracting method: Grinding the husk and/or fruit stem of Xanthoceras sobifolia into particles, immersing the particles by solvents for a predefined time, filtrating the solution, evaporating and condensing the solvents to enrich the filtrate, the concentrated solution is then passed through microporous resin. Eluting the solution with solvents, reclaiming solvents from the collection, the residual, after distilled and dried to form solid brown, is the effective compositions called total saponins. Dissolving the total saponins in water, extracting it by normal butyl alcohol, drying it, a brown powder is obtained. For several times of chromatographing the dissolved powder with silica gel and eluting the solution stepwise with 100:35˜60 chloroform/methanol to refine it, a white acerose crystal is obtained which is the new compound called Xanthoceraside.

The solvent according to the process above includes water, methanol, propanol, butyl alcohol and/or acetone. Methanol, propanol, butyl alcohol or acetone is taken 35˜85% of total volume.

The extracting procedure above adopts a method of interval stirring, i.e. stirring the solvent for 1˜5 minutes at the interval of 10˜20 minutes. The extracting procedure will take 1˜3 hours at the temperature of 60˜100° C.

Application of the compound: This compound can be used as a medicine to treat brain diseases and tumors, and/or as a functional health food to prevent and treat brain diseases and tumors.

Advantages of this Invention

The invention has extracted a brand new compound, Xanthoceraside, from the husk and fruit stem of Xanthoceras sobifolia. By indexing CA-CS and SCIFINDER, this compound, as a new member of triterpenoid saponins, has not been found and reported by anyone else. According to the test results on animals, this compound showed positive effect on improving brain functions, i.e. amending the ability of cognition, abating brain anoxemia. From the treatment test on cancer cell in vitro, the compound showed great inhibiting effect on cancers cells. Therefore, this invention not only digs values of husk and fruit stem of Xanthoceras sobifolia, turning it into precious resource, but also develops a new medicine and a functional health food to treat brain diseases and tumors. All its applications are very promising.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: Procedure to extract the new compound from the husk and fruit stem of Xanthoceras Sobifolia.

FIG. 2: Ultraviolet spectrogram of Xanthoceraside (wavelength: 211.6 nm, absorption value: 0.4554, peak height: 0.1920).

FIG. 3: ¹H NMR spectrum of Xanthoceraside. Test condition: solvent: pyd, Temperature: 25.0° C./298.1K, INOVA-500“BMU500”, Relax delay: 2.000 sec, Pulse: 47.0 degrees, Acq time: 1.892 sec, width: 7998.4 Hz, 32 repetitions, FT size: 65536, Total time: 2 min 4 sec. (BUM-500-¹H, δ 0˜12 ppm).

FIG. 4: Enlarged ¹H NMR spectrum of Xanthoceraside(Part I). Test condition: solvent: pyd, Temperature: 25.0° C./298.1K, INOVA-500“BMU500”, Relax delay: 2.000 sec, Pulse: 47.0 degrees, Acq time: 1.892 sec, width: 7998.4 Hz, 32 repetitions, FT size: 65536, Total time: 2 min 4 sec. (BUM-500-¹H, δ 3.0˜7.0 ppm).

FIG. 5: Enlarged ¹H NMR spectrum of Xanthoceraside(Part II). Test condition: solvent: pyd, Temperature: 25.0° C./298.1K, INOVA-500“BMU500”, Relax delay: 2.000 sec, Pulse: 47.0 degrees, Acq time: 1.892 sec, width: 7998.4 Hz, 32 repetitions, FT size: 65536, Total time: 2 min 4 sec. (BUM-500-¹H, 8 0.4˜2.4 ppm).

FIG. 6: ¹³C NMR spectrum of Xanthoceraside. Test condition: solvent: pyd, Temperature: 25.0° C./298.1K, INOVA-500“BMU500”, Relax delay: 1.000 sec, Pulse: 30.0 degrees, Acq time: 0.600 sec, Width: 31421.8 Hz, 8896 repetitions, Line broadening: 3.5 Hz, FT size: 65536, Total time: 7 hr 19 min 20 sec. (BUM-500-¹³C, δ 10˜180 ppm).

FIG. 7: Enlarged ¹³C NMR spectrum of Xanthoceraside(Part I). Test condition: solvent: pyd, Temperature: 25.0° C./298.1K, INOVA-500“BMU500”, Relax delay: 1.000 sec, Pulse: 30.0 degrees, Acq time: 0.600 sec, width: 31421.8 Hz, 8896 repetitions, Line broadening: 3.5 Hz, FT size: 65536, Total time: 7 hr 19 min 20 sec. (BUM-500-¹³C, δ 1˜50 ppm).

FIG. 8: Enlarged ¹³C NMR spectrum of Xanthoceraside(Part II). Test condition: solvent: pyd, Temperature: 25.0° C./298.1K, INOVA-500“BMU500”, Relax delay: 1.000 sec, Pulse: 30.0 degrees, Acq time: 0.600 sec, width: 31421.8 Hz, 8896 repetitions, Line broadening: 3.5 Hz, FT size: 65536, Total time: 7 hr 19 min 20 sec. (BUM-500-¹³C, δ 51˜94 ppm).

FIG. 9: ¹³C NMR spectrum of Xanthoceraside(Part III). Test condition: solvent: pyd, Temperature: 25.0° C./298.1K, INOVA-500“BMU500”, Relax delay: 1.000 sec, Pulse: 30.0 degrees, Acq time: 0.600 sec, Width: 31421.8 Hz, 8896 repetitions, Line broadening: 3.5 Hz, FT size: 65536, Total time: 7 hr 19 min 20 sec. (BUM-500-¹³C, δ 100˜155 ppm).

FIG. 10: ¹H-¹³C COSY of Xanthoceraside. Test condition: solvent: pyd, Burker-ARX-300, TE: 300K, D1: 1.00000000 sec, P1: 9.80 μsec, AQ: 0.1311220 sec, NS: 48, SWH: 3906.250 Hz, SI: 1024. (ARX-300, ¹H-: δ 0˜10 ppm, ¹³C-: δ 0˜180 ppm).

FIG. 11: Enlarged ¹H-¹³C COSY of Xanthoceraside(Part I). Test condition: solvent: pyd, Burker-ARX-300, TE: 300K, D1: 1.00000000 sec, P1: 9.80 μsec, AQ: 0.1311220 sec, NS: 48, SWH: 3906.250 Hz, SI: 1024. (ARX-300, ¹H-: δ 0.7˜2.3 ppm, ¹³C-: δ 10˜40 ppm).

FIG. 12: Enlarged ¹H-¹³C COSY of Xanthoceraside(Part II). Test condition: solvent: pyd, Burker-ARX-300, TE: 300K, D1: 1.00000000 sec, P1: 9.80 μsec, AQ: 0.1311220 sec, NS: 48, SWH: 3906.250 Hz, SI: 1024. (ARX-300, ¹H-: δ 0.2˜3.4 ppm, ¹³C-: δ 5˜60 ppm).

FIG. 13: Enlarged ¹³C-¹H COSY of Xanthoceraside(Part III). Test condition: solvent: pyd, Burker-ARX-300, TE: 300K, D1: 1.00000000 sec, P1: 9.80 μsec, AQ: 0.1311220 sec, NS: 48, SWH: 3906.250 Hz, SI: 1024. (ARX-300, ¹H-: δ 3˜7 ppm, ¹³C-: δ 60˜140 ppm).

FIG. 14: ¹³C-¹H HMBC of Xanthoceraside. Test condition: solvent: pyd, Temperature: 25.0° C./298.1K, I NOVA-500 “BMU500”, Relax delay: 1.000 sec, Acq time: 0.206 sec, Width: 4973.9 Hz, 2D Width: 30165.9 Hz, FT size: 2048×2048, Total time: 2 hr 18 min 44 sec. (BMU-500, ¹H-:F₂ 0.6˜9 ppm, ¹³C-:F₁ 10˜180 ppm).

FIG. 15: Enlarged ¹³C-¹H HMBC of Xanthoceraside(Part I). Test condition: solvent: pyd, Temperature: 25.0° C./298.1K, I NOVA-500 “BMU500”, Relax delay: 1.000 sec, Acq time: 0.206 sec, Width: 4973.9 Hz, 2D Width: 30165.9 Hz, FT size: 2048×2048, Total time: 2 hr 18 min 44 sec. (BMU-500, ¹H-: F₂ 0.8˜5.1 ppm, ¹³C-: F₁ 100˜180 ppm).

FIG. 16: Enlarged ¹³C-¹H HMBC of Xanthoceraside(Part II). Test condition: solvent: pyd, Temperature: 25.0° C./298.1K, INOVA-500 “BMU500”, Relax delay: 1.000 sec, Acq time: 0.206 sec, Width: 4973.9 Hz, 2D Width: 30165.9 Hz, FT size: 2048×2048, Total time: 2 hr 18 min 44 sec. (BMU-500, ¹H-: F₂ 0.54˜2 ppm, ¹³C-: F₁ 15˜90 ppm).

FIG. 17: Enlarged ¹³C-¹H HMBC of Xanthoceraside(Part III). Test condition: solvent: pyd, Temperature: 25.0° C./298.1K, INOVA-500 “BMU500”, Relax delay: 1.000 sec, Acq time: 0.206 sec, Width: 4973.9 Hz, 2D Width: 30165.9 Hz, FT size: 2048×2048, Total time: 2 hr 18 min 44 sec. (BMU-500, ¹H-: F₂ 2.8˜6.8 ppm, ¹³C-: F₁ 10˜94 ppm).

FIG. 18: Enlarged ¹³C-¹H HMBC of Xanthoceraside(Part IV). Test condition: solvent: pyd, Temperature: 25.0° C./298.1K, INOVA-500 “BMU500”, Relax delay: 1.000 sec, Acq time: 0.206 sec, Width: 4973.9 Hz, 2D Width: 30165.9 Hz, FT size: 2048×2048, Total time: 2 hr 18 min 44 sec. (BMU-500, ¹H-:F₂ 3.4˜6.4 ppm, ¹³C-:F₁ 10˜94 ppm).

FIG. 19: ¹H-¹H COSY of Xanthoceraside. Test condition: solvent: pyd, BRUKER-ARS-300, TE: 300K, D1: 1.50000000 sec, P1: 9.80 μsec, AQ: 0.1311220 sec, NS: 48, SWH: 3906.250 Hz, SI: 512. (ARX-300, δ 0˜10 ppm).

FIG. 20: Enlarged ¹H-¹H COSY of Xanthoceraside. Test condition: solvent: pyd, BRUKER-ARS-300, TE: 300K, D1: 1.50000000 sec, P1: 9.80 μsec, AQ: 0.1311220 sec, NS: 48, SWH: 3906.250 Hz, SI: 512. (ARX-300, & 0.5˜7 ppm).

FIG. 21-1: MS spectrum of Xanthoceraside.

FIG. 21-2: MS² spectrum of Xanthoceraside.

DESCRIPTION OF THE INVENTION IN DETAIL Example 1

Take 2,000 g husk of Xanthoceras sobifolia, as shown in FIG. 1, grind it to particles the size of 30 meshes, extract it by using 35%(v/v) alcohol in 10 times the husk volume for 3 hours at temperature of 60° C. During extraction, stir the solvent for 1 minute every other 10 minutes, filtrate the extracting solution, reclaim alcohol and collect the residual. Elute the collection by using 35% alcohol through macroporous resin Model 101, enrich the effective composition, remove impurity, reclaim again the solvent, dry the residual, then the brown solid remained which is total saponins. Have the total saponins dissolved in water, extract it by using normal butyl alcohol, reclaim normal butyl alcohol, dry the left solution, then brown powder obtained. Subject the obtained aqueous extracts repeatedly to column chromatography over silica gel, elute it stepwise with 100:(35˜60) of chloroform:methanol, reclaim the eluted solution and re-crystallized, will yield 50 mg white raphide which is the invention compound, Xanthoceraside.

Xanthoceraside on Animal Test:

20 female and male mice weighted 18˜23 g were selected and divided evenly into two groups. The treatment group was fed with total dose of Xanthoceraside at the ratio of 9 mg/kg mice weight, and the control group was fed with the same amount of normal saline. After 40 minutes, they were put into Y maze respectively for performance observation. The number of incorrect alternations for a mice were recorded before it made correct choices continuously for 10 times. If errors more than 30, cutting the value to 30. The results are as follows:

TABLE 1 The effects of Xanthoceraside on improving the learning and memory ability of mice Number Error frequency Treatment of mice Dose (mg/kg) (X ± SD) p-value Normal saline 10 same volume 28.2 ± 4.4 — Xanthoceraside 10 9  6.9 ± 2.3 <0.01

The data indicated that the Error frequency by the mice who took Xanthoceraside was significantly less than those who took normal saline (p<0.01). This shows Xanthoceraside has the function of improving mice's memory and study ability.

Example 2

Take 2,000 g fruit stem of Xanthoceras sobifolia and grind it, as shown in FIG. 1, extract it by using 85%(v/v) normal butyl alcohol in the 8 times volume of the fruit stem of Xanthoceras sobifolia for 1 hour at temperature of 75° C. During extraction, stir the solution for 5 minutes every other 20 minutes, filtrate the extracting solution, reclaim normal butyl alcohol and collect the residual. Elute the collection by 85% normal butyl alcohol through macroporous resin Model 101, enrich the effective composition, remove impurity, reclaim again the solvent, dry the residual, then the brown solid remained which is total saponins. Have the total saponins dissolved in water, extract it by using normal butyl alcohol, reclaim normal butyl alcohol, and dry the left solution, then brown power obtained. Subject the obtained aqueous extracts repeatedly to column chromatography over silica gel, elute stepwise with 100:(35-60) of chloroform:methanol, reclaim the eluted solution and re-crystallized, will yield 45 mg white raphide which is the invention compound, Xanthoceraside.

Xanthoceraside on Animal Test:

Mice were trained based on the stochastic three arms Y maze test, to screen those who had less than 30 errors of alternation before they continuously made correct choices for 10 times. After relaxed for 24 hours, the selected ones were randomized into two groups and for all of them scopolamine was injected into celiac at the ratio of 2.0 mg/kg mice weight to cause their learning and memory impairment. After 15 minutes, the mice in the treatment group were given an injection of total dose of Xanthoceraside at ratio of 6 mg/kg mice weight, while those in the control group were given an injection of the same amount of normal saline. After 20 minutes, they were arranged respectively into Y maze and the number of incorrect alternations before they made correct choices continuously for 10 times. The result is shown as follows:

TABLE 2 The effects of Xanthoceraside on recovering the memory retrieval impairment of mice induced by scopolamine Number Error frequency Treatment of mice Dose (mg/kg) (X ± SD) p-value Normal saline 8 same volume 17.9 ± 3.6 — Xanthoceraside 8 6  4.0 ± 1.5 <0.01

From the above table, it shows that Xanthoceraside has the function of recovering the memory retrieval impairment of mice induced by scopolamine.

Example 3

Take 1,000 g husk and 1,000 g fruit stem of Xanthoceras sobifolia and grind them respectively, extract them by using 50%(v/v) alcohol in 10 times volume of the husk and fruit stem of Xanthoceras sobifolia for 2 hours at temperature of 90° C. During extraction, stir the solution for 3 minutes every other 15 minute, filtrate the extracting solution, reclaim alcohol and collect the residual. Elute the collection by 50% alcohol through macroporous resin Model 101, enrich the effective composition, remove impurity, reclaim again the solvent, dry the residual, then the brown solid remained which is total saponins; Have the total saponins dissolved in water, extract it by using normal butyl alcohol, reclaim normal butyl alcohol, dry the left solution, then brown powder obtained; Subject the obtained aqueous extracts repeatedly to column chromatography over silica gel, elute it with 100:(35˜60) of chloroform:methanol, reclaim the eluted solution and re-crystallized, will yield 50 mg white raphide which is the invention compound, Xanthoceraside.

The above obtained Xanthoceraside was for the test of regular static hypoxia tolerance in an isolated environment to observe the effect of Xanthoceraside on death time of animals.

The test consisted of two sections. Each section was divided into two groups: control and treatment. There were three measurements to calculate death time of the mice. Those in treatment group took oral dosing of 2 mg of Xanthoceraside twice a day for 6 days. The three parameters are:

-   -   The average death time of whole group (xt);     -   The super average death time (xp): based on the average death         time of the control group (xc), calculate the death time (xp),         which is greater than the control group (xc), and calculate the         mean.     -   The delayed death time (xp-xc): the super average death time         (xp) minus the control group (xc) and calculated the mean.

The test results are shown in Table 3.

TABLE 3 The effect of Xanthoceraside on mice's death times Indices Control group Treatment group p-value First section: xt (min)   34.5 ± 8.89(30※) 41.84 ± 15.35(30) <0.025 xp(min) 41.42 ± 4.48(14) 56.51 ± 14.59(17) <0.05 xp − xc(min) 5.54 4 ± 46(14)   14.59 ± 14.83(17) <0.05 Second section: xt (min) 25.38 ± 4.24(40) 31.55 ± 6.68(41)  <0.001 xp(min) 27.54 ± 2.87(24) 33.40 ± 4.94(33)  <0.001 xp − xc(min)  2.64 ± 2.87(24) 8.40 ± 4.94(33) <0.001 ※number of mice

According to the results from table 3, it has significant differences for all the three measurements of death time among the control and treatment groups in two sections. Since mice's death time in treatment is longer than the time in control group, it can be verified that Xanthoceraside has the function to increase the level of hypoxia tolerance.

The brain is excessively sensitive to hypoxia because brain is the first organ to be affected. Xanthoceraside strengthens the ability of hypoxia tolerance so that it extends the death time of mice.

Example 4

Take 2,000 g husk of Xanthoceras sobifolia and grind it, as shows in FIG. 1, extract it by using boiling water in 15 times the husk volume for 3 hours. During extraction, stir the solvent for 2 minutes every other 10 minutes, filtrate the extracting solution and partition through macroporous resin Model 101, elute it by water, enrich the effective composition, remove impurity, vaporize to concentrate the extracts, separate the extracts from water with normal butyl alcohol, reclaim normal butyl alcohol, dry the solvent, then brown powder remained, chromatograph the dissolved powder repeatedly through silica gel column, elute it with 100:(35˜60) of chloroform:methanol, reclaim the eluted solution and re-crystallized, then obtain 40 mg white raphide which is the invention compound, Xanthoceraside.

Also, Methanol, propanol or acetone can be used as the extracting solvent in the invention.

Example 5

Take Xanthoceraside derived from the example 3 to do a test on tumor cell in vitro. The methods and results are shown in Table 4.

TABLE 4 The anti-tumor activity assays of Xanthoceraside against six human tumor cell lines in vitro Dyeing method Dose (Tumor (μg/ Observed Testing IC₅₀ No. cell model) ml) indices effects Result (μg/ml) 1 MTT 0.5 Inhibition 9.34 + 41.29 (HL-60 human 5.0 ratio 17.68 leukemia) 50.0 (%) 56.90 2 SRB 0.5 Inhibition −13.90 + 40.98 (PC-3MIE8 5.0 ratio −7.63 human prostate 50.0 (%) 92.03 cancer) 3 SRB 0.5 Inhibition −11.71 + 40.24 (BGC-823 human 5.0 ratio −5.92 gastric cancer) 50.0 (%) 92.45 4 SRB 0.5 Inhibition −4.50 + 18.58 (MDA-MB-435 5.0 ratio 2.92 human breast 50.0 (%) 93.14 cancer) 5 SRB 0.5 Inhibition −9.78 + 39.32 (Bel-7402 human 5.0 ratio −1.24 liver cancer) 50.0 (%) 92.96 6 SRB 0.5 Inhibition −12.72 + 34.23 (Hela cervical 5.0 ratio −4.05 cancer) 50.0 (%) 95.49 MTT: Tetrazolium salt (for dyeing cells), SRB: Sulforhodamine B (for dyeing cells). IC₅₀: The inhibitory concentration of 50% cells.

From the above table; Xanthoceraside exhibits a significant effect on the inhibition of six kinds of human tumor cells in vitro. For breast cancer the IC₅₀ of 18.58 μg/ml of Xanthoceraside is found to have an anti-tumor activity. The other five, such as cervical carcinoma, liver cancer, gastric cancer, stomach cancer, prostate cancer and leukaemia are in turn with IC₅₀ of 34.23 μg/ml, 39.32 μg/ml, 40.24 μg/ml, 40.98 μg/ml and 41.92 μg/ml, respectively. Therefore, Xanthoceraside shows the better inhibition effect on tumor cell at low density. With further research, the new medicine may be developed on tumors.

The compound, Xanthoceraside, derived in example 1, 2, 3, and 4, is analyzed to label the data and identify the structure based on the chemical method and the spectral method, the later including UV, ID-NMR, 2D-DMR, EI-MS and ESI-MS, etc. According to the data from UV, ESI-MS, ¹H-NMR, ¹³C-NMR, HMQC, HMBC, TOCSY (the detailed information was showed in FIG. 2˜21), and refer to following documents: [1] Chen Y J, Takeda t, Ogihara Y. Studies on the constituents of Xanthoceras sorbifolia Bunge. III. Minor prosapogenins from the fruits of Xanthoceras sorbifolia Bunge, [J]. Chem. Pharm. Bull., 1985, 33(1):127-134; [2] Yoshikawa M, Harada E, Matsuda H, et al. Elatosides A and B, potent inhibitors of ethanol absorption in rats from the bark of Aralia elata Seem.: The structure-activity relationships of oleanolic acid oligoglycosid [J]. Chem. Pharm. Bull., 1993, 41(11): 2069-2071. [3] Yoshikawa M, Harada E, Murakami T, et al. Camelliasaponins B1, B2, C1, and C2, new type inhibitors of ethanol absorption in rats from the seeds of Camellia japonica L. [J]. Chem. Pharm. Bull., 1994, 42(3):742-744, the structure of the compound is 3-O-(α-L-arabiofuranosyl(1→3)-β-D-galactopyranosyl(1→2))-β-D-glucuronopyranosyl-21,22-diangeloyl-R1-barrigenol. Its chemical structure is:

The detailed data of the compound obtained by the chemical method and the spectrum method are listed in Table 5.

TABLE 5 NMR results of Xanthoceraside No ¹³C-NMR ¹H-NMR Aglycone moiety 1 39.7 2 26.7 3 89.9 3.21(1H, m) 4 39.0 5 55.7 6 18.9 7 36.4 8 41.1 9 47.2 10  37.0 11  24.0 12  125.5 5.48(1H, brs) 13  143.7 14  47.8 15  67.6 16  73.4 17  48.4 18  41.5 19  47.0 20  36.8 21  78.6 6.70(1H, d, J = 10.2 Hz) 22  73.6 6.32(1H, d, J = 10.2 Hz) 23  28.0 1.26(3H, s) 24  16.8 1.16(3H, s) 25  15.8 0.81(3H, s) 26  17.6 0.98(3H, s) 27  21.3 1.84(3H, s) 28  63.2 3.73, 3.50(1H, d, J = 10.2 Hz) 29  29.6 1.09(3H, s) 30  20.3 1.31(3H, s) Sugar moiety 3-o-glucuronopyranosyl moiety  1′ 105.2 4.89(1H, d, J = 10.2 Hz)  2′ 78.9  3′ 86.4  4′ 71.7  5′ 77.3  6′ 172.0 2′-O-β-D-galactopyranosyl moiety 1 104.9 5.32(1H, d, J = 7.5 Hz) 2 73.5 3 75.2 4 69.8 5 76.7 6 61.9 3′-O-α-L-arabinofuranosyl moiety 1 111.2 6.03(1H, brs) 2 83.6 3 77.7 4 85.5 5 62.4 Angeloyl moiety 1 167.8 2 129.0 3 137.4 5.96(1H, q, J = 7.0 Hz) 4 15.9 2.09(3H, dq, J = 7.0 Hz) 5 21.0 2.00(3H, m) 1 168.2 2 129.2 3 136.6 5.76(1H, q. J = 6.6 Hz) 4 15.7 1.93(3H, dq, J = 6.6 Hz) 5 20.7 1.72(3H, m)

To summarize the above description, the finding of the new compound increased the family member of triterpenoid saponins, which substantially enhanced the comprehensive utilization value of the husk and fruit stem of Xanthoceras Sobifolia. It is very promising that new medicines will be developed to cure brain diseases and tumors. 

What is claimed:
 1. In a functional health food wherein the improvement comprises an effective amount of Xanthoceraside to improve memory, concentration or hypoxia tolerance, wherein Xanthoceraside has formula (I):

and wherein the Xanthoceraside is in a white raphide crystalline form.
 2. A method for treating a subject with a cognitive impairment comprising, administering an effective amount of Xanthoceraside to the subject, wherein Xanthoceraside has formula (I):

and wherein the Xanthoceraside is in a white raphide crystalline form.
 3. The method according to claim 2, wherein the effective amount of Xanthoceraside is in a food as a supplement.
 4. The method according to claim 2, wherein the cognitive impairment involves memory loss.
 5. A process for isolating Xanthoceraside from the husk or fruit stern of Xanthoceras sobifolia Bunge comprising: grinding the husk or fruit stem of Xanthoceras sobifolia Bunge into particles having a mesh size of about 30 mesh, covering the particles with an aqueous mixture of a C1-C4 alcohol or acetone having a concentration of about 35% to about 85% and then stirring, filtering, evaporating, and condensing the aqueous extract to form a concentrated extract solution, introducing the concentrated extract solution to column chromatography on an adsorbent macroporous resin to obtain a saponin extract solution; drying the saponin extract solution to obtain a saponin powder, dissolving the saponin powder in water to obtain a solution, extracting the solution with n-butanol, drying the extract and solubilizing, subjecting the solution to silica gel chromatography, eluting with a 100:35-60 chloroform:methanol solution to obtain an eluate, and crystallizing the eluate to yield a white raphide.
 6. The process of claim 5, wherein stirring is for about 1 to about 5 minutes every 10-20 minutes for about 1 to about 3 hours at a temperature of about 60° C. to about 100° C.
 7. A method for treating a subject with hypoxia comprising, administering an effective amount of Xanthoceraside to the subject, wherein Xanthoceraside has formula (I):

and wherein the Xanthoceraside is in a white raphide crystalline form. 